Experimental Analysis Results on the BFS 58-1-I1 Critical Assembly

Abstract

Experimental analyses have been performed on the BFS-58-1-I1 core, which was assembled at the BFS-2 fast critical assembly of Russian Institute of Physics and Power Engineering(IPPE). Special feature of the core is having “non-Uranium fuel zone” in the center, where the A12O3 pellets used for replacing the UO2 pellets significantly softened neutron spectrum. Accordingly, effects of both heterogeneous cell model and group constant set on the nuclear parameters were studied prior to the whole core calculation. By considering the results, reasonable C/E values were obtained for spectrum index, criticality and sodium void reactivity using JNC’s analysis method applied for fast reactor cores. The cross-section adjustment technique was employed in order to verify the consistency between the BFS data and the JUPITER data. As no serious problem was found in the consistency check, good prospects were obtained for utilizing the BFS experimental data in developing JNC’s nuclear design database.